Security considerations, network capability considerations, or other like considerations may prompt an organization or service provider to restrict transmittal of packets having certain characteristics, for instance, packets directed to certain domains. As an example, some organizations or providers may implement a blacklist functionality for their network such that access is restricted to any domains included in a blacklist. Some organizations or providers may instead, or in addition, implement a whitelist functionality such that access is allowed only to those domains included in the whitelist. Accordingly, packets entering or traversing such a network may need to be filtered based on this blacklist or whitelist functionality.